Flavonoids are polyphenols that are found in numerous edible plant species. Data obtained from preclinical and clinical studies suggest that specific flavonoids are chemo-preventive and cytotoxic against various cancers via a multitude of mechanisms. However, the clinical use of flavonoids is limited due to challenges associated with their effective use, including (1) the isolation and purification of flavonoids from their natural resources; (2) demonstration of the effects of flavonoids in reducing the risk of certain cancer, in tandem with the cost and time needed for epidemiological studies, and (3) numerous pharmacokinetic challenges (e.g., bioavailability, drug–drug interactions, and metabolic instability). Currently, numerous approaches are being used to surmount some of these challenges, thereby increasing the likelihood of flavonoids being used as chemo-preventive drugs in the clinic. In this review, we summarize the most important challenges and efforts that are being made to surmount these challenges.

The epithelial-to-mesenchymal transition (EMT) has received significant interest as a novel target in cancer prevention, metastasis, and resistance. The conversion of cells from an epithelial, adhesive state to a mesenchymal, motile state is one of the key events in the development of cancer metastasis. Polyphenols have been reported to be efficacious in the prevention of cancer and reversing cancer progression. Recently, the antimetastatic efficacy of polyphenols has been reported, thereby expanding the potential use of these compounds beyond chemoprevention. Polyphenols may affect EMT pathways, which are involved in cancer metastasis; for example, polyphenols increase the levels of epithelial markers, but downregulate the mesenchymal markers. Polyphenols also alter the level of expression and functionality of important proteins in other signaling pathways that control cellular mesenchymal characteristics. However, the specific proteins that are directly affected by polyphenols in these signaling pathways remain to be elucidated. The aim of this review is to analyze current evidence regarding the role of polyphenols in attenuating EMT-mediated cancer progression and metastasis. We also discuss the role of the most important polyphenol subclasses and members of the polyphenols in reversing metastasis and targeting EMT. Finally, limitations and future directions to improve our understanding in this field are discussed.

Thienopyrimidines containing a thiophene ring fused to pyrimidine are reported to have a wide-spectrum of anticancer efficacy in vitro. Here, we report for the first time that thieno[3,2-d]pyrimidine-based compounds, also known as the RP series, have efficacy in prostate cancer cells. The compound RP-010 was efficacious against both PC-3 and DU145 prostate cancer (PC) cells (IC₅₀ < 1 µM). The cytotoxicity of RP-010 was significantly lower in non-PC, CHO, and CRL-1459 cell lines. RP-010 (0.5, 1, 2, and 4 µM) arrested prostate cancer cells in G2 phase of the cell cycle, and induced mitotic catastrophe and apoptosis in both PC cell lines. Mechanistic studies suggested that RP-010 (1 and 2 µM) affected the wingless-type MMTV (Wnt)/β-catenin signaling pathway, in association with β-catenin fragmentation, while also downregulating important proteins in the pathway, including LRP-6, DVL3, and c-Myc. Interestingly, RP-010 (1 and 2 µM) induced nuclear translocation of the negative feedback proteins, Naked 1 and Naked 2, in the Wnt pathway. In addition, RP-010 (0.5, 1, 2 and 4 µM) significantly decreased the migration of PC cells in vitro. Finally, RP-010 did not produce significant toxic effects in zebrafish at concentrations of up to 6 µM. In conclusion, RP-010 may be an efficacious and relatively nontoxic anticancer compound for prostate cancer. Future mechanistic and in vivo efficacy studies are needed to optimize the hit compound RP-010 for lead optimization and clinical use.

Multidrug resistance (MDR) is a continuing clinical problem that limits the efficacy of chemotherapy in cancer. The over expression of the ATP-binding cassette (ABC) family G2 (ABCG2) transporter is one of the main mechanisms that mediates MDR in cancer. Molecular modeling data indicated that cariprazine, a dopamine D₂/D₃ receptor partial agonist, had a significant binding affinity for ABCG2 transporter with a Glide XP score of −6.515. Therefore, in this in vitro study, we determined the effect of cariprazine on MDR resulting from the overexpression of ABCG2 transporters. Alone, cariprazine, at concentrations up to 20 μM, did not significantly decrease cell viability. Cariprazine, at concentrations ranging from 1 to 10 μM, did not significantly alter the cytotoxicity of mitoxantrone (MX) in the parental non-small cell cancer cell line, H460 and colon cancer cell S1. However, cariprazine (1–20 μM) significantly enhanced the efficacy of ABCG2 substrate antineoplastic drug MX in the ABCG2-overexpressing MDR cell line, H460-MX20 and S1M1-80, by reducing the resistance fold from 28 to 1 and from 93 to 1.33, respectively. Cariprazine, in a concentration-dependent (1–20 μM), significantly increased the intracellular accumulation of Rhodamine 123 in S1M1-80. Interestingly, 10 or 20 μM of cariprazine significantly decreased the expression levels of the ABCG2 protein in the colon and lung cancer cell lines, suggesting that cariprazine inhibits both the function and expression of ABCG2 transporters at nontoxic concentrations. Overall, our results suggest that cariprazine, via several distinct mechanisms, can resensitize resistant cancer cells to mitoxantrone.

A significant number of anticancer drugs fail to treat primary and metastatic brain tumors primarily because of the complex blood-brain barrier (BBB) and overexpression of ATP-binding cassette (ABC) transporters, which decrease drug penetration into the central nervous system and ultimately into tumors. It is noteworthy that the ABC transporters, ABCB1 [known as P-glycoprotein (P-gp)] and ABCG2 [known as breast cancer resistance protein (BCRP)], are overexpressed in brain tumors, including common gliomas. The co-presence of these transporters may negate the inhibition of either transporter, particularly if both transport the same anticancer drug. The cellular export of drugs by ABC transporters has been implicated in mediating resistance to anticancer drugs. However, the clinical relevance as a therapeutic target in human tumors remains a matter of contention. Although effective and clinically approved ABC transporter inhibitors could potentially overcome drug resistance, none are currently approved. Furthermore, the ABC transporter inhibitors in clinical trials produced low or no clinical efficacy, significant toxicities, and unsuitable pharmacokinetic profiles. Therefore, innovative approaches are needed to efficaciously and simultaneously inhibit these transporters to surmount anticancer drug resistance. This review emphasizes the clinical significance of ABC transporters in diminishing the efficacy of brain tumor treatments. The molecular alterations in BBB following brain tumor development, which are linked to various cancer therapies, are discussed. The overexpression of ABCB1 and ABCG2 at the BBB is discussed, potential strategies to decrease the export of chemotherapeutics by these transporters and the associated challenges and failures are discussed, and the implementation of novel approaches is considered.

Aim of Study Urinary tract infections (UTIs) are among the most common infections affecting individuals of different ages worldwide. Antimicrobial agents are usually the first-line treatment for UTIs, and the use of the prescribed antibiotic is escalating, resulting in increased rates of bacterial resistance and UTI recurrence. The current study aimed to identify the causative bacteria in Jordan, to explore their resistance pattern to antibiotics, and to describe drug-related problems associated with UTI management. Methods This prospective, descriptive study was conducted in two major health institutions in two cities in Jordan over a period of six months. The study population included inpatients and outpatients diagnosed with UTIs. Patients' data were collected directly from patients using data collection sheet and from patients’ charts. Results A total of 273 patients were included, of whom 56.4% were women. Urine cultures were obtained from 81% of the patients. E. coli was the most common causative pathogen (50.6%), followed by K. pneumonia (10.8%). Extended spectrum beta-lactamase (ESBL) producing E.coli was the most commonly detected organism across all types of UTIs. Ceftriaxone and imipenem/cilastatin were most commonly administered to hospitalized patients, whilst ciprofloxacin and co-triamzaxole were the most commonly prescribed in outpatient clinics. The susceptibility results for parenteral antibiotics showed high rates of resistance to cefazolin and ticarcillin. Additionally, high rates of resistance to fluoroquinolones were identified. Further, several drug-related problems were identified. High rates of resistance to commonly prescribed antibiotics were detected. Drug-related problems (i.e., inappropriate antibiotic dosage, unnecessary antibiotic prescribing, inappropriate duration of therapy, and prescribing of ineffective antibiotics) were relatively common. Conclusion The present study highlights the need for clinical pharmacists to manage the high level of drug related problems by providing updated information about proper drug selection, rational drug use, and patient education and counselling.